Reports of something odd in Iliamna go back to the Aleut and other indigenous tribes, although no one knows how far back in time these stories began. The Aleuts did not hunt the lake’s creatures, and believed them to be dangerous to men fishing in small boats. Some early white settlers and visitors reportedly saw the things, too, but the stories about Iliamna did not gain wide circulation until the 1940s, when pilots began spotting monsters from the air. The flyers’ descriptions generally matched the native tales. The lake’s mystery inhabitants were most often described as long, relatively slender animals, like fish or whales, up to 30 feet in length.

In 1988, bush pilot and fishing guide Babe Alsworth (commonly misspelled Aylesworth) recounted his 1942 sighting in an interview with cryptozoologist Loren Coleman. Alsworth saw several animals, each well over 10 feet long, in a shallow part of the lake. He said they had fishlike tails and elongated bodies. He described the color as dull aluminum. Larry Rost, a survey pilot for the U.S. government, saw a lone creature of the same type while crossing the lake at low altitude in 1945. Rost thought the animal was over 20 feet long.

There have been at least three attempts to find or catch Iliamna’s mystery inhabitants. In the 1950s, sportsman Gil Paust and three companions (one a fisherman named Bill Hammersly, who had been in the plane with Alsworth in 1942 and shared his amazing sighting), tried to fish for the creatures. According to Paust, something grabbed the moose meat used as bait and snapped the steel cable it was hooked to. (Admittedly, this sounds like a tall tale, although there’s no proof either way.) In 1959, oilman and cryptozoology enthusiast Tom Slick hired Alsworth to conduct an aerial search of the lake, but nothing was sighted. An expedition in 1966 also apparently met with no success, as no results were announced.

In 1979, the Anchorage Daily News offered $100,000 for tangible evidence of the Iliamna creatures. The reward brought both serious and non-serious researchers (one man reportedly played classical music to lure the animals up). There were no results. Apparently, there has never been a well-financed expedition with sophisticated sonar and underwater photographic gear.

According to a 1988 article in Alaska magazine, a noteworthy (but unnamed) witness was a state wildlife biologist. In 1963, this official was reportedly flying over the lake alone when he spotted a creature which appeared to be 25 to 30 feet long. In the ten minutes it was under observation, the thing never came up for air. Other flying witnesses mentioned in media accounts include a geologist who flew over the lake with two companions in 1960, reportedly spotting four 10-foot fish, and air taxi pilot Tim LaPorte in 1977.

In LaPorte’s case, the veteran pilot and air-service owner was near Pedro Bay, at the northeast end of the lake. He was flying just a few hundred feet above a flat calm surface. LaPorte and his two passengers, one a visiting Michigan fish and game official, saw an animal lying still, its back just breaking the surface. As the plane came closer, the creature made a big arching splash and dove straight down. LaPorte remembers watching a large vertical tail moving as the animal sounded. Comparing the object to an 18-foot boat often observed from the same altitude, LaPorte and his companions estimated the thing was 12 to 14 feet long. LaPorte described the object as either dark gray or dark brown. LaPorte had been a passenger in a different aircraft in 1968 when the other two individuals in the plane had a very similar sighting. (In that incident, LaPorte, who was in the left seat, could not see the animal from his side.)

Modern sightings have occurred mostly near the villages of Iliamna and Pedro Bay. It was off the latter town in 1988 that several witnesses, three in a boat and others on shore, reported one of the creatures. In this case, it was described as black. One witness thought she could see a fin on the back, with a white stripe along it.

Lake Iliamna is still an isolated body of water, its shores largely unpopulated. The largest village, Kakhonak, counts only 200 permanent residents. The lake cannot be reached overland. Summer visitors must come by boat or fly in to a single airstrip. If there are unusual creatures in the lake, it’s hardly surprising that a long time can pass between good sightings.

A common theory about the Lake Iliamna creatures (sometimes called Illies) is that they are gigantic sturgeon. These could be either an outsized population of a known type or an unknown species. Sturgeon - huge fish with armorlike scutes covering their backs and a heritage going back before the dinosaurs - match most descriptions from Iliamna fairly well. A witness named Louise Wassillie, who watched a creature from her fishing boat in 1989, said specifically, It’s only a fish. It was about 20 feet long and had a long snout. Probably a sturgeon. “

Biologist Pat Poe of the Fisheries Research Institute (FRI) at the University of Washington, who has studied the salmon populations in Iliamna and neighboring Lake Clark, once commented, “I’m sure there’s a big fish. I think the lakes have a lot of interesting secrets. We don’t know much about other resident fish in the lake.” Warner Lew, currently the senior biologist with the FRI’s Alaska Salmon Program, agrees the lake seems a suitable habitat for large sturgeon. Lew reports several witnesses have told him of sighting giant fish, but he has yet to see any fish larger than a four-foot Northern pike in his 24 years of research visits to the lake.